Retrofit your home with double
glazing for maximum comfort!
Hello, we are the masters of warmer winters, cooler summers, and healthy homes!
Nothing beats a home that is cosy, warm and dry in winter and comfortably cool in the summer.

Welcome to Thermaseal – specialists in retrofit double glazing for you home. Although, we prefer to say specialists in warmer winters, cooler summers, quieter nights and dryer, healthier homes!

Being a Christchurch company, we know just how cold some older Canterbury homes can get. We’re turning that around one house at a time, by converting existing single glazed aluminium windows to double glazing with our own unique powder coated beading system.

When you deal with Thermaseal, you’re dealing directly with the manufacturer, which means we can give your home all the benefits of double glazing without the time, hassle or cost of starting from scratch. When you talk with Thermaseal, you talk directly with the manufacturer of your new double glazing.

No middleman.

No miscommunication.

And you can rest assured in your warmer, quieter home, knowing you’re protected by a
10 year Thermaseal warranty.
What is retrofit?

Changing to double glazing doesn't mean throwing away your existing aluminium windows. With a small modification to your existing frames and beads, we can remove the existing single glazing from your existing windows and replace with new insulated, energy efficient, double glazed panels.

The benefits of retrofitting your existing aluminium windows include; Warmer in winter & cooler in summer, reduction in energy costs, reduces condensation, noise reduction, increases security, reduces draughts, adds value to your property and reduces fading from UV.

Retrofit also offers significant cost savings when compared to completely replacing all your windows.

We can retrofit your existing aluminium windows of any size, shape or colour. We will colour match all existing colours as close as possible, fit our exclusive bead and fit new sashes (opening windows) to your existing joinery.

Your home will look like it's been double glazed from day one!
How It Works
There’s a fair bit of complex science behind our double glazing and the various glass technologies and options, but the benefits are clear as, well... glass!

Glass Options

You don't need to make all the decisions here and now as you might need a variety of different glass typed in your home for optimum thermal and performance benefits. Our trained consultants will take you on that journey and help you to make the best decision for you and your home, but here's a brief overview of some of the available performance options and an image that shows the performance of each.

Glass Colours: Clear, Green or Grey

Standard Double Glazing
- Standard glass panels filled with dehydrated air (Standard IGU)

High Performance Double Glazing
- Argon gas is a thermal insulating gas which fills the air gap between the glass panels and further enhances the insulation performance (Argon Gas IGU)
- Low E coated glass for superior thermal performance (Low E Glass IGU)
- Low E glass + Argon gas filled unit (Low E Argon Glass IGU)

Safety Glass
- Acoustic laminate - a safety glass with a 99% UV filter for sun protection of your furnishings and noise reduction benefits
- Heat toughened safety glass

Obscure Glass
- For privacy

And for the ins and outs on the Insulating Glass Unit Manufacturers Association (I.G.U.M.A).

Other Glass Products
- Cat doors
We don't just do double glazing, Thermaseal can also offer the supply and installation of cat doors in a single or double glazed door or window panel.
How Thermaseal Retro Fitted Double Glazing Works
Keep warm in the winter, and stay
cool in the summer with Thermaseal
About Us
Loyalty & Demand
Thermaseal was formed in 1991 and operated out of a central city premises. Strong demand and customer loyalty enabled us to grow and move first into a larger purpose built modern factory and showroom in Wigram, Christchurch, but we have now outgrown that and recently made our second move to a newer, bigger, purpose built factory at 926 Halswell Junction Road, in the Waterloo Business Park, Christchurch.
Our investments in state-of-the-art machinery together with well trained fabricators ensure that we can provide a high standard of double glazing to our customers. All our units are tested by BRANZ and comply with the EN 1279 and BS5719 standard.
Reputation & Respect
We market largely on the strength of our reputation and do not employ commissioned salespeople or canvas over the phone. We have a totally non-invasive sales policy.
Contact Us /
Get a Quote
Like what you’ve seen? Well once our double glazing is installed, it FEELS even better! So all that’s left, is for you to get in touch...

    How did you hear about us?

    Thermaseal Double Glazing
    Waterloo Business Park
    926 Halswell Junction Road, Christchurch 8025

    PO Box 16562
    Christchurch 8441